<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<link rel="stylesheet" type="text/css" href="css/cssReset.css"/>
		<style type="text/css">
			ul{
				background: rgb(51,51,51);
				margin-top: 10px;
				padding: 10px 0;
			}
			li{
				width: 100px;
				height: 30px;
				line-height: 30px;
				margin: 0 20px;
				float: left;
				position: relative;
				text-align: center;
				color: white;
			}
			li a{
				color: white;
				
			}
			li div:first-of-type{
				content: "";
				position: absolute;
				left: 0;
				top: 0;
				width: 10px;
				height: 10px;
				border-top: 1px solid royalblue;
				border-left:1px solid royalblue;
				transition: all 0.3s;
				box-sizing: border-box;
				
			}
			li div:last-of-type{
				content: "";
				position: absolute;
				right: 0;
				bottom: 0;
				width: 10px;
				height: 10px;
				border-bottom: 1px solid royalblue;
				border-right:1px solid royalblue;
				transition: all 0.4s;
				box-sizing: border-box;
			}
			
		</style>
	</head>
	<body>
		<ul class="clearfix">
			<li>
				<div></div>
				<a href="#">博客园</a>
				<div></div>
			</li>
			<li>
				<div></div>
				<a href="#">首页</a>
				<div></div>
			</li>
			<li>
				<div></div>
				<a href="#">新随笔</a>
				<div></div>
			</li>
			<li>
				<div></div>
				<a href="#">管理</a>
				<div></div>
			</li>
			<li>
				<div></div>
				<a href="#">联系</a>
				<div></div>
			</li>
		</ul>
	</body>
	<script src="js/jquery-1.8.3.min.js" type="text/javascript" charset="utf-8"></script>
	<script type="text/javascript">
		$("li").mouseenter(function(){
			$(this).find("div").css({"width":"100px","height":"30px"});
		})
		$("li").mouseleave(function(){
			$(this).find("div").css({"width":"10px","height":"10px"});
		})
	</script>
</html>
